A cartridge container unit having a compartment for storing a material. The compartment is adapted for separately storing one component of a formulation until ready for mixing with a second component in an assembly unit prior to use. Thus, the cartridge unit allows the user to store a material until ready for use, or to store multiple components of a formulation in separate individually sealed containers until ready for use that can be readily assembled into a single multi-compartment container. The cartridge unit includes a substantially cylindrical housing having a sealable opening at its top end and an opening at its bottom end. The bottom end may be adapted and configured to engage and seal the assembly unit. A first inwardly extending annular shoulder is provided between the sealable opening and the bottom opening, defining a flow passage along a longitudinal axis of the housing.